Ga. Code § 48-2-48
If the commissioner ascertains that the return of any taxpayer (or dealer pursuant to Article 1 of Chapter 8 of this title) contains mistaken, false, or fraudulent statements or that it contains statements or omissions of data which are otherwise incorrect or misleading, and that as a result thereof improper or inadequate assessments of taxes have been made, the commissioner may determine and fix the amount of the taxes due from the taxpayer or dealer and shall proceed to collect the state tax due pursuant to the determination. In any case in which property assessments are made by the commissioner under the law for purposes of local taxation, the commissioner shall certify amounts of any property omitted from previous assessments to the proper local tax authorities for taxation in the local tax districts. All taxes collected under this Code section shall bear interest at the rate specified in Code Section 48-2-40, unless otherwise provided by law, from the date the commissioner advises the taxpayer in writing of the amount of the taxes due, until paid. The interest shall be assessed and collected as a part of the tax.
OCGA § 48-2-48